DEVELOPMENT OF VIRTUAL CAVE EXPLORATION ENVIRONMENT USING LIDAR AND SFM PHOTOGRAMMETRY

In these days, virtual reality is a useful instrument to do activities and exploration that are difficult for an audience. Also, VR is increasing as a tool to develop accessibility and inclusion of people with disabilities, elderly, children and others. Our project consisted in the development of a virtual cave exploration environment obtained from real data by using underground LiDAR (Light Detection and Ranging)and SFM (Structure From Motion) Photogrammetry. LIDAR is a surveying method that measures distance to a target by illuminating the target with pulsed laser light (infra-red) and measuring the reflected pulses with a sensor.The Geoslam ZEB1 LiDAR was used to obtain the measurements. This system provides us with more than 40,000 data points per second in a random three-dimensional pattern with a 270^o angular field of view. SFM Photogrammetry is the use of photography in surveying and mapping, this method measures distances between objects from two dimensional images and create a 3D structure. The output for both methods are a 3-D point cloud that was used to create a 3-D model of a cave (using Meshlab for LIDAR and Agisoft Photoscan for SFM). Then, the resulted mesh cave models are imported in Unity (game engine) as an object to produce a virtual environment that can be seen with Oculus. The user then can explore (to enhance interest) or study (learn concepts) the virtual cave models. For this study, we will present the results of virtual caves obtained from the Cabachuelas Nature Reserve System in Morovis, PR and the user experience as formal and non-formal education tool.